SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '319273d7a94e98b570c88fada04c41fabedb4b0bf212f161fbe87aadf4954fae' 
  AND token = '7UD8PYONKCJr5B1Y2FzM9Nqqe6xCbw319l6SmbsBHKY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}